Old Flux - does it go bad?

[robert3985]

lol   I remember the first time I heard about Superior No. 30. I ordered some and never got it to work at all. Still have it.

I use thick plumbing flux from Home Depot.

When I started making my own turnouts way back in the 1980's, I was well-versed in soldering electronics since I had been taught how to assemble electronic kits by my Electrical Engineer father at an early age, who also taught me how to solder HO track along with feeders when I was 9 years old.

However, making my own turnouts using PCB tie material I purchased from Rail Craft and their Code70 rail to more closely comply with NTRAK's near-compatibility with Code80 rails caused me to hunt for both a new iron (rather than my trusty soldering gun) along with different solder and a flux that would ease construction.

I happened upon plumbing flux at The Home Depot and decided to give it a try, and whaddya know, it worked great!  I knew it was acidic, so I made sure I washed my bench-constructed turnouts with warm water before installing them on my 12' of NTRAK modules.

Unfortunately, in about a year and a half, I noticed my turnouts were breaking...the copper cladding on the PCB ties was coming off of the fiberglass (or whatever is between the two copper surfaces)...and there was a white, puffy powder on my solder joints that was breaking through my paint.

Eventually, ALL of my turnouts disintegrated, and I trashed the modules, saving the Tortoises and the Rail Craft Code55 I had used for the industrial siding on one 6' module...everything else went into the dumpster.

I was planning a new set of modules for the Club's new, more realistic module standards, and attended The Hostler's Ogden Union Station show and noticed a fellow there who was selling, and making at the same time, N-scale catenary, and so I watched him and asked what kind of flux and solder he used, because it looked incredibly quick and easy for him to assemble and solder his brass catenary tower models.  He introduced me to Superior No.30 Supersafe Soldering Flux as well as 96/4 Tin/Silver, silver-bearing solder...and my turnout building and soldering other metals changed drastically for the better.

However, even the very best soldering flux won't fix bad soldering practices, and I cannot imagine that Superior No.30 Supersafe Flux would cause solder joints to not solder, since I have soldered thousands of rails to PCB boards and other metals together now for over 50 years with absolutely great success using both the liquid and the gel versions.

Yeah, strong acid plumber's flux worked great too, but...it ate my turnouts as well as my ballast after a few years, and I highly DO NOT RECOMMEND IT!...because there's more to soldering model railroad rails than just sticking things together...they have to last...a loooong time...which Superior No.30 Supersafe Self-Neutralizing Soldering Flux does, not just for me, but for many many others who have discovered it and use it.

Cheerio!
Bob Gilmore

Edited - for typos and misspellings

[Sokramiketes]

I like the Superior #30 but don't usually use the 96/4 solder.  For clean joints (soldering together small parts for signals) and adjustability later (as when building turnouts) I always seem to go back to a roll of Kester electronics solder with a touch of lead.  Then everything wets out great, and I can reheat and move. 

I liked the paste and gel versions, but they always seem to revert to liquid no matter what form they start in.  LOL.  I need a better applicator and those metal tube ones look good up thread. 

[peteski]

I liked the paste and gel versions, but they always seem to revert to liquid no matter what form they start in.  LOL.  I need a better applicator and those metal tube ones look good up thread.

I think a perfect disposable applicator is a Microbrush (like the yellow and white on this photo). The one I use is a knockoff brand blue, with a larger head than the yellow one in this photo.  I just dunk it in the bottle and apply to the joint area. It holds just the right amount of liquid (sometimes I do a double dip on larger joints). After the soldering session I just throw it away. I suppose I could rinse and reuse it.

[nickelplate759]

...
The proper way to prep the tip is to always wipe of clean to expose shiny solver color ras you pick up the iron to make a joint, then solder the joint and immediately after clean the tip, apply tin the tip with some fresh solder to build up slightly thicker layer on the tip, then put the iron back in the holder.  Do they ever time you make a joint.  It should be a habit.

The reason apply extra solder to the idling tip is for sacrificing that solder, allowing it to oxidize. So when you clean that solder off the tip immediately before making the next joint you'll have a fresh bright tinned tip ready to make  the next joint.

In the 50 or more years I have soldered (as a hobby and and in professional life), that's how I solder. That's the way I was taught.

Thanks for the refresher @peteski .  With a little practice I'm now able to solder feeders to track and solder rail joiners at joints (no, not all of them!)  without melting the ties.